The present invention relates to a key holding device enabling selective removal of an auxiliary key that serves as a vehicle key normally stored in a vehicle.
In the prior art, various types of vehicle lending systems have been proposed to lend a vehicle to a third person in a state in which conditions for use of the vehicle are restricted. For example, if a vehicle is lent to a third person in a state in which the vehicle may be freely used, the third person may use the vehicle as he or she desires. Japanese Laid-Open Patent Publication No. 2004-25936 describes one example of a vehicle lending system in the prior art. The publication describes a technique in which restrictions are imposed for driving a vehicle when using a sub-key but not when using a master key. When lending the vehicle to a third person, the user gives the sub-key to the third person so as that the vehicle is used under restricted conditions.
In the vehicle lending system of the above-described publication, the master key and the sub-key must both be carried by the user. This is inconvenient since the user must carry more items. Further, for example, if the vehicle must be lent to a third person when the user is not carrying the sub-key, the user must go and find the sub-key. This is also inconvenient to the user.
Therefore, other types of vehicle lending systems, such as an assist key system, have been developed. In an assist key system, a vehicle key (hereinafter referred to as the assist key) that allows use of a vehicle under restricted conditions is normally stored in a vehicle. When lending the vehicle to a third person, the user gives the assist key to the third person to permit usage of the vehicle under restricted conditions. The assist key serves as a sub-key, which is described above, and includes a key code, which sets the restricted conditions for usage of the vehicle. In this case, there is no need for the user to hold two types of vehicle keys. This increases convenience for the user.
In this type of assist key system, the assist key is stored, for example, in a glove box, which is located in the passenger compartment. In this case, for example, the assist key is inserted into a key slot that is formed in the glove box. In a state inserted in the key slot, if the assist key were to be freely removable, anyone would be able to freely remove the assist key from the key slot. This lowers security and may result in the key being stolen. It is therefore preferable that the key slot include a key holding device (key lock-unlock device) that locks the assist key so that it cannot be removed from the key slot. In this case, when the vehicle permits lending of the assist key, it is preferable that the key holding device be unlocked so that the assist key is removable.
If a key holding device was to have a complicated structure and components costs were to be increased, this would cause many obstacles for arrangement of the key holding device in a vehicle. Thus, there is a demand for a key holding device having a simple and inexpensive structure.